The majority of the settlers moving into the Amazon come from the highly populated Andean region. Their movement from the mountains is usually provoked by economic reasons, and is aided by government policies and incentives to occupy the “empty Amazon”.
The presence of settlers has many social and environmental impacts upon the land and the Amazonian indigenous communities who live there. Settlers tend to overexploit thin soils, causing erosion and degradation of the rainforest ecosystem. Many also use damaging (and illegal) fishing methods which kill young fish as well as commercial-size fish, very quickly reducing overall fish stocks, and the increased population density puts high pressure on scarce hunting resources. Settlers moving into remoter regions may also spread diseases amongst local populations, who may not have the necessary immunological defences or good access to health services.
Settlers are also often involved in land conflicts with the local indigenous population, as much of the land they occupy (often legally titled to them by the Government) lies over indigenous territories and areas important economically or culturally to the identity of local indigenous people.
The majority of the information for this section is based on the current situation in the Upper and Lower Urubamba river basin, mainly home to the Machinguenga people where settler numbers are high.